1. Field of the Invention
The present invention relates to an image forming apparatus.
2. Description of the Related Art
Among image forming apparatuses such as copiers and printers, well known are those including a belt-shaped image carrier such as an intermediate transfer belt or a photosensitive belt. For example, Japanese Patent Application Laid-open No. 2006-343629 discloses a conventional image forming apparatus including such an image carrier. The conventional image forming apparatus includes an image transfer unit and a conveying unit. The conveying unit conveys a recording medium to the image transfer unit at such timing that the image transfer unit can accurately transfer an image carried on the image carrier onto a desired position of the recording medium without misalignment.
Japanese Patent No. 2893540 discloses a conventional technology, in which, after the leading edge of a recording medium bumps into a gate member and is positioned, the recording medium is held between the registration rollers located downstream of the gate member. The registration rollers are moved in a width direction while holding the recording medium, so that misalignment of the recording medium in its width direction (in a direction perpendicular to its conveying direction) is corrected. The recording medium is then conveyed to an image transfer unit.
Japanese Patent Application Laid-open No. 2002-265097 discloses another conventional technology, in which, after a recording medium bumps into a gate member (a surface of the gate member) and skew thereof is corrected the recording medium is conveyed to an image transfer unit by a pair of registration rollers located upstream of the gate member.
In the conventional technologies, a surface of the belt-shaped image carrier is arranged to slope from upstream in the conveying direction to the image transfer unit. However, a conveying path to the image transfer unit is arranged to be substantially level in the conveying unit, resulting in waste of space between the image carrier and the conveying unit.
Because of a recent demand for a more compact image forming apparatus in which a recording medium is conveyed at high speed, there is need of a technology for efficiently utilizing space.